208 SOUTHERN PORK PRODUCTION 



containing coal tar derivatives. Of course, the same 

 solutions that are used in the dipping vats may be used 

 in the wallows, but they should only be used in diluted 

 form. The job is usually not so thorough in the case of 

 the wallow as with the vat. 



The hog oiler. — In recent years a number of new de- 

 vices have been placed on the market designed to assist 

 in killing lice on hogs by means of an application of oil 

 to the skin. These have proven quite valuable. They do 

 not take the place of the dipping vat on the hog farm, 

 however. In principle these oilers have a reservoir for 

 holding the crude oil, with a feeding arrangement so that 

 the hog rubs on some part of the machine and the part 

 of the hog rubbed receives a coating of the oil, which 

 will kill all of the lice it comes in contact with. The 

 same results can be secured by tying old grain sacks 

 around rubbing posts and saturating with oil or by pour- 

 ing the oil in the wallows, but these methods are a little 

 more wasteful of the oil than are the patented devices. 



